This invention relates generally to devices for controlling the flow of air in heating, air-conditioning and ventilation systems, hereinafter air flow systems, and more particularly to a damper assembly having adjustably mounted damper vanes and an electro-optical controller for operating, positioning and repositioning the damper vanes to regulate, limit and inhibit flow of air in an air flow system.
The use of airflow for transferring heat, moisture, scents, etc. in an air flow system is well known in the art.
One well-known mechanism for directing, controlling and regulating the quantity of air flowing through or being delivered through the ducts and vents in an air flow system is a damper assembly.
Such damper assemblies for regulating, limiting and inhibiting the airflow in such air flow systems include adjustably mounted damper vanes which may be adjusted manually or by a suitable motor coupled, mechanically, hydraulically or electrically or by combinations of such coupling means, to the damper vanes.
In mechanical/electrical controllers, the electrical switches wear and erode due to electrical arcing and therefore often fail in the normal course of operation and use of a given damper assembly.
Certain patents in the prior art show various types of electro-optical controllers for various applications.
Thus, U.S. Pat. No. 4,871,954 to Rathgeber discloses in column 1, lines 1-20, a motor control device for an air flap in a heating or air-conditioning unit. As shown in column 1, lines 11-17, the ""954 patent discloses that it is known to provide such flaps within the framework of a servo system with a position indicator which reports the position of the flap back to the control device. The position indicator is disclosed by the ""954 patent as being either contacting or non-contacting.
U.S. Pat. No. 4,988,865 to Schmidt et al. discloses a device for determining the angular position of the drive shaft in a sewing machine. As shown, for example, in FIG. 2, the ""865 patent discloses a position signaling device having an opaque disk 3 mounted to the drive shaft. The disk is provided with a first set of slots 4 and a second set of slots 7 spaced circumferentially on the disk. Fixedly positioned and in alignment with each other on opposite sides of the disk are a plurality of light emitters 11 and light receivers 12 to control the device as the device is switched between two or more positions.
U.S. Pat. No. 4,628,239 to Everett, Jr. discloses a photo emitter/sensor assembly 36 and a slotted disk 34 having a plurality of equally spaced slots 40 for controlling the position of a carriage printer. The number of slots corresponds to the number of stop or stepping positions of the driving motor 30 and the shaft 32. A slot is provided in the disk for each stop or stepping position of the stepping motor.
U.S. Pat. No. 5,279,556 to Goi et al. discloses a drive shaft 13 coupled at one end to an electrically driven motor 21 and at the other end to a rotary disk 1. The rotary disk combined with first and second photoelectric detectors 2 and 3 constitute a rotary encoder 4 used to control a peristaltic pump. The rotary disk 1 is provided with a plurality of slits 5 defined along a circular row in a circumferentially equally spaced relationship with each other. The device is provided with a control unit 20 that is designed to execute a predetermined control program in response to the signals from photodetectors to apply a drive control signal.
U.S. Pat. No. 5,003,239 to Matthews et al. discloses a driving motor 42 connected to a drive shaft 46. An encoder wheel 60 is mounted on and rotates in conjunction with drive shaft 46. The encoder wheel is provided with a plurality of equispaced slits or sectors 62 on the outer circumference. Surrounding the outer circumference of the encoder wheel is a U-shaped housing 70. In the U-shaped housing is a pair of optical couplers 72,74. The first optical coupler 72 is oriented to correspond with the plurality of blocker segments 64 on the encoder wheel 60, thus acting to digitally read the blocker 64 and sector segments 62,66. The second optical coupler 74 is oriented radially offset from the radius of the plurality of sectors 62,66 to read a vane 68.
The ""239 patent, as shown in column 5, lines 12-16, further states that the device can be coordinated with the use of stepping motors having different size steps.
The present invention provides an improved damper assembly having adjustably mounted damper vanes operatively associated with an electro-optical controller for operating, adjusting, positioning and repositioning the adjustably mounted damper vanes of a damper assembly in an air flow system from fully open to fully closed or approximately closed or at varying positions between fully open and fully closed, as the operating conditions in the air flow system may require to allow or inhibit the flow of air in the air flow system.
The present invention provides a damper assembly having adjustably mounted damper vanes for regulating, limiting and inhibiting airflow in an air flow system in which the damper vanes are connected to and positioned and repositioned by a suitable motor in turn actuated by an electro-optical controller. The electro-optical controller has an opaque disk fixedly connected and movable with the motor or the coupling connecting the motor to the damper vanes so that the opaque disk at all times reflects and coincides with the relative position of the damper vanes. The opaque disk is provided with a plurality of predetermined circumferentially sized and spaced openings or bores which correspond to the desired positioning and repositioning for the damper vanes. Operatively associated with the shaped and sized openings and bore are coacting pairs of light emitting diodes (LED""s) and phototransistors disposed at fixed circumferentially spaced locations adjacent the front and rear surfaces of the opaque disk for directing signals to a control logic circuit and an associated electronic switch assembly for starting and terminating the motor for the positioning and repositioning of the damper vanes to provide the desired air flow conditions for the air flow system in which the damper assembly is mounted. The size of the holes in the opaque disk can be adjusted for approximately a 3xc2x0-5xc2x0 circumferential movement to match the overshoot or stopping characteristics of the motor for adjusting the damper vanes. The respective location of the openings or bores in the opaque disk and the corresponding fixed locations of each coacting pair of LED""s and phototransistors can also be adjusted to define the open and closed position of the damper vanes. Multiple additional openings or bores in the opaque disk between the bores defining the open and closed position of the damper vanes also associated multiple additional coacting pairs of the light emitting diodes and phototransistors can be provided to establish different open positions for the damper vanes of the damper assembly.
Thus, in accordance with one aspect of the present invention, there is provided a damper assembly having adjustably mounted damper vanes for use in an air flow system having motor means connected to the damper vanes for moving the damper vanes between an open position and a closed position to regulate the volume of air flowing through the air flow system, movable means operatively associated with the motor means and the damper means including means thereon for identifying the relative position between open and closed of the damper vanes, an electronic system including logic circuitry for operating electronic switches to actuate the motor to move the damper vanes between the open and closed position, a light sensing means operatively associated with the identifying means on the movable means for signaling and transmitting responses to the logic circuitry on the relative position of the damper vanes between the open and closed positions to enable the control logic circuitry to actuate the motor means to position the damper means for the desired operation of the associated air flow system.
In accordance with another aspect of the present invention, there is provided an electro-optical control for operating and adjusting the adjustably mounted damper vanes in a damper assembly for an air flow system, from open to closed or approximately closed, as the air flow system may require, to allow and inhibit flow of air in the air flow system. This aspect of the present invention also includes a motor connected to the damper vanes for moving the damper vanes from open to closed position, an opaque disk rotatably mounted and movable on movement of the damper vanes having, at least two bores circumferentially spaced from each other, at least one of such bores corresponding to the open position of the damper vanes and another of the bores corresponding to the closed position of the damper vanes, an electronic assembly including logic circuitry and electronic switches for actuating the motor, and respective pairs of sensing and transmitting means fixedly mounted in predetermined spaced relation for operative association with the bore corresponding to the open position and the bore corresponding to the closed position of the damper vanes. The respective pairs of sensing and transmitting means are for signaling the position of said damper vanes to the electronic assembly to actuate the motor for positioning and repositioning the damper vanes in accordance with such signals.
Accordingly, it is an object of the present invention to provide a damper assembly having adjustably mounted damper vanes coupled to a motor for moving the damper vanes which also includes an electro-optical controller for actuating the motor which eliminates mechanical/electrical switches heretofore used for actuating such motors and replaces them with non-contacting coacting pairs of light sensing and detecting members for signaling electronic switches to operate the motor so as to eliminate the continuous wear and electrical arcing common to such mechanical/electrical switches.
It is another object of the present invention to eliminate the mechanical/electrical switches for operating the motor to adjust the relative position of the damper vanes in a damper assembly heretofore used in prior art devices and to replace them with non-contacting electronic switches and an electro-optical controller for actuating such motors so as to lengthen the functional operating life of the damper assembly.